Bionomic Characterisation of Benthic Communities on Rocky Shores of Lipsi Island (Aegean Sea, Greece)

Rocky shores are important transitional environments between terrestrial and marine ecosystems. Although the Greek coastline is the largest in the Mediterranean basin, scant information is available regarding the benthic communities populating its shores. Here, we characterised the benthic communities inhabiting the rocky shores of Lipsi Island (Greece). The littoral zones of nine different sites were surveyed by randomly selecting 10 photo-quadrats from each zone, and estimating species richness, coverage, and abundance of the OTUs (Operational Taxonomic Units) recorded. Data analysis consisted of a comparison among the littoral zones, followed by comparisons between sheltered and exposed sites. A total of 44 OTU s were identified with the presence of a single Non-Indigenous Species (NIS), the algae Caulerpa cylindracea. The results showed a steep increase in species richness and coverage from the supralittoral to the upper infralittoral zone, most likely due to the mild environmental conditions of this zone in comparison with the other two zones. Species richness, mean coverage and abundance of organisms were found to be higher at sheltered sites, except for the supralittoral zone, where Melarhaphe neritoides was more abundant at exposed sites, most likely due to the continuous wetting of spraying water. Filter-feeders and species well adapted to high hydrodynamic conditions were mostly found at the exposed sites, while turf showed a higher coverage at sheltered sites, underlining the effect of wave exposure in shaping the composition of shallow benthic communities. This study provides a first description of the benthic communities inhabiting the rocky shores of Lipsi Island, establishing an important baseline to assess potential future alterations and develop conservation measures.